React Native - Scan Local Network for Hosts - network-programming

is there any function, extension or tutorial which supports scanning of local network for hosts.
I like to scan the local networks for all Raspberry Pi computers.
Thanks for any hint.

You can use lan scan library. But currently it has support for only Android. I myself is looking for a solution to scan ip cameras on local network. Here is a link
https://github.com/Odinvt/react-native-lanscan
Also there is a objective C library if you can write binding for react.
https://github.com/mongizaidi/LAN-Scan
I have only this much knowledge on topic right now. Will post further if i find something.

Related

ESP32: Is it possible to make a bridge ETH-WIFI

i m using olimex esp32-poe-iso and i m trying to achieve the following:
HOME ROUTER ====== (WIFI) ====== (STA):esp32-poe-iso:(ETH) ====== (ETH cable)===== Jetson Nano
im not trying to find a piece of code here. I m just trying to be sure that it's doable.
i have been trying for days now with no luck.
All the docs and examples out there explain the opposite way around. which worked fine for me.
HOME ROUTER ====== (ETH) ====== (ETH):esp32-poe-iso:(WIFI-AP) ====== (WIFI)===== Jetson Nano
Any clue is really appreciated
You want to build a WiFi bridge which allows your wired Jetson Nano board to connect to your WiFi network? Sure, it's possible. Not simple, but definitely doable (assuming you know your networking). At least one person has source code, but googling for "esp32 wifi bridge" brings up quite a few resources.
I'm not sure that the Espressif WiFi library gives you enough control to do it transparently. So we're probably talking about building a NAT box, which requires translating the addresses for your wired client and forwarding the packets. Maybe also a DHCP server, if you don't like to assign IP-s manually. There's a sample NAT implementation here: https://github.com/martin-ger/esp32_nat_router
A more practical solution would be buying a WiFi router which can work as a bridge for Ethernet devices. Some very cheap WiFi routers have this functionality these days (I vaguely recall a TP-LINK device which cost around 20€).

Requirements to access IP Camera using OpenCV

I'm new to IP cameras and I know there are quite a lot of topics about this in the forum already, but I can't find a concrete answer for my needs.
I want to access an IP camera using OpenCV in Python from a Windows PC. As I don't have a camera yet, I need to buy one and I can't figure out, what requirements this camera needs to have.
For example, there are quite cheap IP cameras (e.g. Xi****) which say they come with an Android or iOS app and are only accessible via those.
I thought you can access any IP cam via OpenCV, but now I'm not sure anymore... can anyone give me an overview, what specs an IP cam needs, to be accessed via OpenCV on Windows? I don't want to buy a camera and later realize, that I can't access the video stream.
I'm really sorry, if this has already been asked, but I can't find a satisfying answer to this question and Google doesn't seem to be very helpful...
Thanks in advance.
check for IP cam that can transmit RTSP opencv know how to work with this type of stream.

Looking for someone that is familiar with QNX 4.2

As per topic. I have very old machine that i cannot replace (some old railway machine). That machine still uses 3.5zip drive. I need to fit the USB instead. Therefore, as i`m completely not familiar with this system, can someone direct me please on where to start to reconfigure this ( if manageable of course) for use with USB? I guess there would a need for drivers etc so the USB is discoverable.
Thanks a lot in advance.
You'll need to download io-usb (the USB server) and Fsys.usb (the USB bulk storage driver).
Start here:
http://foundry27.com/sf/wiki/do/viewPage/projects.qnx4/wiki/InstallationNotesForUSBStack?selectedTab=versions&version=4
Continue here:
https://openqnx.com/phpbbforum/viewtopic.php?t=11230

Can I use google assistant library in python program without raspberry pi?

I have been looking a lot to use google assistant in a python program, but all I found was to create a personal assistant using raspberry pi. I just want to use the google assistant library in a program on my laptop and not raspberry pi.
You can definitely use the same Python scripts across platforms. A raspberry pi is a handy device for putting together an embedded device, but isn't necessary. The gRPC calls will work anywhere. The library does have certain restrictions to work with either the raspberry pi or Ubuntu.

How to connect usb webcam to ev3?

I would like to connect an USB webcam to my EV3.
is it possible to do that?
and how can I do it and how can I reach the cam from my code?
I use Labview for programming
and thanks in advance :)
Both leJOS and ev3dev support USB web cams connected to the EV3 brick, however, neither work with LabView.
To get this working on the official LEGO firmware, you need to compile proper kernel modules, sideload them on the EV3 and as suggested in the comments, sideload another program that converts the image data into something that can communicate with labview remotely.
use bellow vi to convert image to 2d array use array tool to cut appropriate part
and do not forget for average use this equation otherwise the answer will be wrong
ave=r/3 + b/3 +g/3 not r+b+g/3
vi

Resources